Table of contents: Examination ↓ Replacement ↓
On models since 1995, two CKP sensors are used, one of which (rEF sensor) is installed in the front part of the power unit, on the aluminum section of the engine oil pan, directly under the crankshaft pulley. It is used to determine the number of grooves of the crankshaft pulley rotor sensor in relation to the TDC positions of the piston of each of the cylinders (120° signal). The second sensor (POS) is also located on the aluminum section of the oil pan, but on the rear side of the power unit, near the transmission dome and is used to determine the shaft speed (1° signal). Both sensors consist of a permanent magnet, a core and a wire winding. A change in the gap entails a change in the parameters of the magnetic field in the immediate vicinity of the sensor, which, in turn, leads to a change in the amplitude of the signal voltage output by the sensor to the PCM. The PCM uses the information received from the CKP sensors when adjusting the ignition timing settings, injection synchronization and detecting misfires.
 |
 |
Examination
Note: Performing the following procedure may cause a fault to be stored in the OBD memory and the Check Engine Light to be illuminated. Once the check and any necessary repairs have been completed, be sure to clear the system memory (see section On-Board Diagnostics (OBD) System - Operating Principle and Error Codes).
Sensor SKR REF
Disconnect the sensor wiring connector and connect an ohmmeter to the contact terminals. At a temperature of 20°C, the required resistance is 470÷570 Ohm. A faulty sensor must be replaced. If the measurement result complies with the nominal requirements, refer to the electrical connection diagrams (see Chapter On-board electrical equipment) and check the condition of the electrical wiring in the section of the circuit between the sensor and the PCM. Make sure that there are no signs of a violation of the quality of the grounding of the black wire of the sensor wiring harness. If no violations can be found, the car should be driven to a service station for diagnostics of the PCM condition and the appropriate repair.
Source is available on the resource: NissanBook.ru
SKR POS sensor
1. Disconnect the wiring from the sensor. Turn on the ignition. Check for battery voltage at the red wire terminal of the harness side connector. If there is no voltage, check the wiring condition in the circuit section between the ECCS relay and the battery (don't forget to check the condition of the fuses first). Check that the ECCS relay and its wiring to the sensor are in good working order (see wiring diagrams at the end of the Chapter On-board electrical equipment). Check for the presence of voltage with an amplitude of 5.0 V at the terminal of the white wire. If voltage is absent, check the condition of the circuit in the section between the PCM and the sensor. If the circuit is in good condition, drive the car to a service station to diagnose the condition of the PCM and perform the appropriate repair. Also make sure that there are no signs of poor grounding of the black wire of the harness.
2. Remove the sensor. Turn off the ignition and connect the sensor wiring to it. Connect the positive probe of the voltmeter to the terminal of the black wire on the back of the connector (for more details, see Chapter On-board electrical equipment). Ground the negative probe to ground. Turn on the ignition. Momentarily touch the tip of the sensor with a metal object (type of screwdriver). At the moment of contact, the voltmeter should register a reading of 5.0 V. When the metal is removed, the signal amplitude should quickly drop to zero. The faulty sensor must be replaced. Note: In rare cases, the reason for entering the fault code may be a violation of the integrity of the flywheel/drive disk ring gear.
Replacement
1. Disconnect the electrical wiring from the sensor.
2. Unscrew the mounting bolt and remove the sensor. Installation is performed in the reverse order.